fix(ff-a): module plat_ffa missing configs

In the module plat_ffa, the 'source_set' for both the spmc and
hypervisor were missing arch-specific configuration. As a result of the
missing configuration, the auxiliary macros defined in 'vm_ids.h' could
assume unexpected values for the given configuration.

Change-Id: I39c772a97bf854a7b860c02da9a5bafbd402d735
Signed-off-by: J-Alves <joao.alves@arm.com>
diff --git a/src/arch/aarch64/plat/ffa/BUILD.gn b/src/arch/aarch64/plat/ffa/BUILD.gn
index b811376..6eb6f9e 100644
--- a/src/arch/aarch64/plat/ffa/BUILD.gn
+++ b/src/arch/aarch64/plat/ffa/BUILD.gn
@@ -14,14 +14,20 @@
 }
 
 source_set("hypervisor") {
-  public_configs = [ "//src/arch/${plat_arch}:config" ]
+  public_configs = [
+    "//src/arch/${plat_arch}:config",
+    "//src/arch/${plat_arch}:arch_config",
+  ]
   sources = [
     "hypervisor.c",
   ]
 }
 
 source_set("spmc") {
-  public_configs = [ "//src/arch/${plat_arch}:config" ]
+  public_configs = [
+    "//src/arch/${plat_arch}:config",
+    "//src/arch/${plat_arch}:arch_config",
+  ]
   sources = [
     "spmc.c",
   ]